Safety Software Cams And Safety Cam Track (Sn); Safety Software Cams And Safety Cam Track - Siemens SINUMERIK 840D sl Function Manual

05.08
6.8

Safety software cams and safety cam track (SN)

Description
The "safe software cams" function (SN) can be used to implement safe electronic
cams, safe range detection or working zone/protection zone delimination for spe-
cific axes, thereby replacing the hardware solution.
Warning
!
The enabled cam signals are immediately output when the control system is
powered–up, this output is however only safe after safe referencing (this is
signaled using the SGA "Axis safely referenced").
The cams are only considered as being safe if they were safely referenced. This is
the reason that the user must interlock this SGA with the cam SGA.
Features
The most important features include:
S Cam positions are safely defined and evaluated as a software function
S Working ranges/zones are defined
Tolerance for SN
Owing to variations in the clock cycle and signal run times (signal propagation
times), the cam signals of the two monitoring channels do not switch simulta-
neously and not precisely at the same position. A tolerance bandwidth can there-
fore be specified for all cams using the following machine data/parameters. Within
this bandwidth, the signal states for the same cam may be different in the two
monitoring channels.
for 840D sl:
MD 36940: $MA_SAFE_CAM_TOL
for SINAMICS S120:
p9540: SI motion SCA (SN) tolerance (Control Unit)
Note
The lowest possible tolerance bandwidth (less than 5–10 mm) should be selected
for the "safe software cams" function. It makes sense to parameterize the cam
tolerance greater than or equal to the actual value tolerance.
© Siemens AG 2008 All Rights Reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 05.2008 Edition
Safety Functions Integrated in the System/Drive
6.8 Safety software cams and safety cam track (SN)
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